Hydraulic rotary engine



Aug. 29, 1939. c. O.J.,MONTELIUS 2,171,146

HYDRAULIC ROTARY ENGINE Filed April 14, 1938 2 Sheets-Sheet 1 I I5 34 32 20 2/ '76 9 /0 /2 1 f8 P M 20 27 l 25 5/ O 26 35 t 30 1g 57 "[4 7 I 24 c INVENTORII CARL OSCAR JOSEF MONTELIUG AJLTORNEKS C. O. J. MONTELIUS HYDRAULIC ROTARY ENGINE- Filed April 14, 1938 2 Sheets-Sheet 2 Q a WE 7 8 w 2 f W a 7 w w W R 84 fi/ MW) 1 fi w W um 0 1 5 w m\ 5 1m d x YIWT k\ J 7 W M A INVENTO CARL. OSCAR JOSEF'MONTEEIUS ,BYQ MJEM $44K.

, TOR N 5V5 Gil Patented Aug. 29, 1939 UNITED STATE HYDRAULIC ROTARY ENGINE Carl Oscar Josef Montelius, Stockholm, Sweden,

assignor to Aktiebolaget Imo-Industri, Stockholm, Sweden, a. corporation of Sweden Application April 14, 1938, Serial No. 201,941

In Sweden December 2, 1936 9 Claims.

and creeping speeds up to a given maximum value, either forwards or backwards.

Still another object of the invention is to provide a hydraulic rotary engine of the class described adapted to operate as a motor actuated by a pressure fluid in which engine the additional friction at the start of a driven shaft is eliminat- "ed and a quick speed control of said shaft is secured.

Still another object of the invention is to provide a hydraulic rotary engine of the class described, comprising two rotors both of which are actuated by a pressure fluid, a differential gear connecting said rotors with a common driven or driving shaft, respectively, and a device for varying the ratio of the speeds of the rotors.

These and further objects of the invention will be apparent according as the following description proceeds, reference being had to the accompanying drawings in which, embodiments of the invention are illustrated by way of example.

In the drawings:

Figure 1 is a vertical sectional view of a hydraulic .motoNaccording to the invention;

Fig. 2 is a sectional view on line IIII of Fig.

Fig. 3 is a diagrammatical view of a hydraulic transmission according to the invention;

Fig. 4 is a longitudinal sectional view of the hydraulic motor thereof;

Fig. 5 is a cross-sectional view along the lin V-V in Fig. 4; and

Fig; 6 is a diagrammatical view of the differential gear of the motor.

The central rotor i4 is rotatably supported by. means of stud shafts l6 and I1 running in bearings in the end caps I2.

Fluid under pressure is supplied through an inlet |8 to the central chamber l9, whence the liquid passes to both sides through the axial bores in the housing driving the twin screw sets l4, l5 and through openings 2|] in the end caps l2 into the spaces 2| between the rotor housing H and the external casing M, the fluid then escaping through the outlet 22.

Provided at one end of the screw motor is a differential gear comprising a rotatable drum 29 keyed to the driven shaft 30 and supported by a ball bearing 23 fixed to the housing In and by a bearing 24 fitting to the shaft end 24 of the rotor 4. Mounted on studs 28in the drum 29 are two bevel planet wheels 21, andengaging said planet wheels are two bevel sun wheels and 26, one, 25, secured to the adjacent end cap' l2 of the rotary housing II and the other, 26, fixed to the rotor l4.

Provided at the opposite end of the screw motor is a mechanical braking device comprising two brake disks 3| and 32 slidably but non-rotatably mounted one, 3|, on the stud l5 and the other, 32, on the end cap l2 of the housing H. The disks are disposed in a space, which is divided into two chambers 35 and 35 by a partition 34. The partition 34 has brake surfaces on opposite sides adapted to co-operate with corrgsponding brake surfaces on the disks 3| and 3 chamber 36 an opening 38, said openings serving as inlet and outlet ports for the pressure fluid.

The apparatus described operates in the following inanner:

On its passage through the hydraulic motor the fluid causes the rotors II and I4 and, consequently, the sun wheels 25 and 26 to rotatein opposite directions. If the sun wheels 25 and 26 rotate at equal speeds, the driven shaft 3|] is at rest.

when fluid under pressure is supplied to one of the openings 31 or 38, the corresponding disk 3| or 32 is forced towards the partition 34 so as In the embodiment illustrated in Figs. 1 and o produce braking action on the c ponding 2, l0 designates an external casing and H 3. cylindrical housing ofa screw motor, said housing being provided with two end caps |2 rotatably mounted in ball bearings l3 in the external casing l0. The housing is-provided with axial intersecting bores for a cehtral rotor 14 and 'two lateral rotors l5, each of said rotors in the illustrated embodiment being shaped as twin screws.

rotor l4 or H and, consequently, to change the ratio between the absolute speeds of said rotors. This causes the driven shaft 3|l'to be rotated in the one or the other direction. If, for instance, pressure fluid is supplied through the opening 31, the disk 3| will be forced towards the partition 34 and the speed of the rotor l4 and, consequently, also that of the gear wheel 26 will be reduced.

The chamber 35 has an opening 31 and the Thus, the speed of the wheel 25 in the diflerential gear will exceed the speed of the wheel 26 causing the driven shaft 30 to be rotated in the same direction as the wheel 25. If, however, liquid is supplied through the opening 38, the disk 32 will be more or less retarded so that the speed of therotor housing ii and, consequently, also of the wheel 25 is reduced. The driven shaft is hereby caused to rotate in the opposite direction. If one of the disks 3| or 32 is brought to stand-still, the shaft 30 will have a speed equal to half the speed 'of the unrestrained rotor. Thus, it is possible to impart to the driven shaft 36 a speed varying from .zero to a certain value in the one or the other direction depending upon the magnitude of .the braking action applied on the renumeral 48 designates a pump driven by a motor 4| and circulating a fluid by means of a pressure conduit 42 and a return conduit 43 through a differential motor having an inlet 45 and an outlet 41, saiddiiferential motor being shown in detail in Figs. 4 and 5.

The differential motor which is shown in detail in Figs. 4 and 5 comprises a motor housing 50, a central body 5| and a differential gear casing 52. The motor housing 50 has an end cover '68 and two bores 53 and 54 each enclosing a' screw set. The one screw set comprises alefthand threaded power screw 55 meshing with two right-hand threaded side screws 56. The shaft 51 of the screw 55 is supported by a ball bearing 58 mounted in the body5i and carries at its end a gear wheel 59. The other screw set comprises a left-hand threaded power screw 60 mesh- 1 ing with two right-hand threaded sidescrews 6|. The shaft 62 of the screw 66 issupported by a ball bearing 63 mounted in the body 5| and carries a gear wheel 64 mounted loosely on the shaft 62 and meshing with the wheel 59 on shaft 51. The gear wheel 64 has an extended hub 65 which at its end is shaped to form a pinion 66. Near its end shaft 62 carries another pinion 61.

The inlet 45 (Fig. 3)\opens into an inlet chamber 16 formed in the central body 5| and common to the two screw sets. 'At' the other end of the screw sets are valve chambers 1i and 12 communicating with the outlet 41 (Fig. 3).

The differential gear comprises a drum 13 and a cover 14 fixed thereto, said drum and cover being supported by ball bearings 15 and 16, the one 15 secured to the gear casing 52 and the other 16 fixed to ashield 11 secured to the casing and supported by the central body 5|. Rotatably.

journalled in the drum 13 are two planet g'ear wheels 88 and 8| and similarly journalled in the cover 14 are two planet gear wheels 82 and 83, said four planet wheels engaging each other as shown in Fig. 6. Pinion 61 engages planet wheels 86 and 8| (but not 82 and'83) and pinion 66 engages planet wheels 82, 83' (but not 88 and 8|). The drum 13 is integral with the driven shaft 84.

The speed of the screws 55, 60 is controlledby a throttle valve having a valve body 98 .controlling the outlets 9| and 92 from bothvalve chambers 1|, 12 and secured to a stem 93 hav- .-ing a manoeuvring knob 94 (see Fig. 5).

When the fluid passes from the inlet 19 along the screw sets to the outlet valve chambers 1| and 12, the power screws 55 and 60 are rotated in the direction indicated by the arrows in Fig. 4, causing the pinions 66 and 61 to rotate in opposite directions. When the valve body 96 assumes its middle neutral position (see Fig. 5) the fluid is allowed to pass freely from both chambers 1| and 12, the power screws 55 and 60 then rotating at the same speed. In this case the drum 13 and the driven shaft 84 are at :stand-still. When the valve stem 93 is moved for instance downwards 'in Fig. 5, the flow from chamber 12 is throttled causing the speed of screw 55 to be reduced. Assuming the quantity of liquid delivered by pump 40 per unit of time being constant, a greater portion of the total flow will then pass the screw set 68, 6| causing their speed to be increased to the same degree as that of the screw set 55, 56 is' decreased. As a result shaft 84 will be rotated at a speed equal to half the difference between the speeds of the screws 55, 60. When the outlet 92 of chamber 12 is entirelyshut, the screw 55 will be at.standstill and the screw 60 will rotate at twice its initial speed, shaft 84 rotating at half this speed and in the same direction as before. If the valve stem 93 is moved upwardly, the passage from chamber 1| is throttled causing the speed of the screw 66 to be reduced and that of screw 55 to be increased, with the result that the shaft 84 will rotate in opposite direction as before.

The apparatus described is simple in operation and affords perfect speed control of shaft 84 from stand-still and creeping speeds, forwards or backwards, up to a given maximum-value.

The gear wheels 59, 64 may be of different diameters, for instance having the ratio 1:2 and the diameter of the pinion 66 maybe made twice as great as that of pinion 61. Thereby it will be possible toreduce the diameters of the planet gear wheels and, thus, that of the drum 13. Or six planet gear wheel s may be used in which case the pinions 66-and 61 engage each three of these six wheels. This slightly more complicated design is preferred for larger output giving considerably smaller dimensions.

The screw set 55, 56 may be threaded in a direction opposite to that of the screw set 60, 6 I. If in this case the gear ratio of the wheels 59, 64 is different from 1:1 the shaft 84 tvlll always rotate in the same direction irrespective of whether the outlet 1| or the outlet 12 is throttled, but

-when throttling ,one of said outlets the driving torque of the shaft -84 will be different from that obtained when throttling the other outlet.

In the following claims the expression differential gear is used to indicate any device in which two rotary movements serve to produce a third rotary movement proportional to the"difference between or the sum of the first-mentioned rotary movements;

What I claim is: 1. A hydraulic rotaryengine, comprising two rotatable members each adapted to be actuated by a pressure fluid, a differential gear comprising a rotary drum having a shaft, two sun wheels and a plurality of planet wheels rotatably mounted on said drum, means for connecting each of said rotatable memberswith one of said sun wheels,

and means for controlling the flow of fluid through at least one of said rotatable members. 2. A hydraulic rotary engine, comprising two rotatable members each adapted to be actuated bya pressure fluid, a differential gear comprising a rotary drum having a shaft, two sun wheels and a plurality of planet wheels rotatably mounted on said drum, means for connecting each of said rotatable members with one of said sun wheels, and means for braking thespeed of at least one of said rotatable members.

3. A hydraulic rotary engine, comprising two rotatable members each adapted to be actuated by a pressure fluid, a difl'erential gear comprising a rotary drum having a shaft, two sun wheels and a plurality of planet wheels rotatably mounted on said drum, means for connecting each of said rotatable members with one of said sun wheels, means for braking the speed of at least one of said rotatable members, and hydraulically operated means for controlling said braking means.

4. A hydraulic rotary engine, comprising a plurality of intermeshing rotary screws, a rotatable .housing for said screws, said screws and housing speeds of said screws and housing.

5. A hydraulic rotary engine, comprising two sets of intermeshing rotary screws, a fixed housing for said screws, said sets of screws being adapted to be actuated by a pressure fluid, a

shaft, a differential gear connecting said sets of screws with said shaft, and means for varying the ratio of the speeds of said sets of screws.

6. A hydraulic rotary engine, comprising two rotable members each adapted to be actuated by a pressure fluid, a differential gear comprising a rotary drum having a shaft, two sun wheels and a plurality of planet wheels rotatably mounted on said drum, means for connecting each of said rotatable members with one of said '7. A hydraulic transmission, comprising a power driven pump adapted to deliver liquid,

two rotatable members adapted to be actuated by said liquid, a shaft, a differential gear connecting said rotatable members with said shaft, and means for varying the ratio of the quantities of liquid leaving the rotatable members thereby varying the speed of said shaft.

8. A hydraulic transmission, comprising a power driven pump adapted to deliver liquid, two rotors adapted to be actuated by said liquid, inlet and outlet for the liquid to and from said rotors, a shaft, a differential gear connecting said rotors with said shaft, and means for varying the quantity of liquid flowing through each of the rotors thereby varying the speed and the direction of rotation of the shaft.

9. A hydraulic transmission, comprising a power driven pump adapted to deliver liquid, two

sets of intermeshing screws adapted to be actusets of screws, a shaft, a differential gear connecting said sets of screws .with said shaft, and

means for throttling said outlets for varying thespeed and the direction of rotation of the shaft.

' CARL OSCAR JOSEF MONTELIUS. 

